Samuel mccaetee



(No Model.)

S MOOA'RTER.

DEVICE FOR OLAMPING PLATES OR SHEETS OF METAL.

No. 373,672. Patented Nov. 22, 1887.

WITNESSES: I INVENTOR M 4 1% W 6 W ATTORNEY UNITED STATES PATENT 1Erica,

SAMUEL MGOARTER, OF NORRISTOVVN, PENNSYLVANIA, ASSIGNOB TO JOHN D.NEWBOLD, OF SAME PLACE. r

DEVICE FOR CLAMPING PLATES OR SHEETS OF METAL.

SPECIFICATION forming part of Letters Patent No. 373,672, dated November22,1887.

Serial No. 246,023. No model.)

To all whom it may concern.-

Be it known that I, SAMUEL .MOGARTER, a citizen of the United States,residing at Norristown, in the county of Montgomery and State ofPennsylvania, have invented certain new and useful Improvements inScrew- Olamps for Boiler or Sheet-Metal Plates, of which the followingis a specification.

My invention has relation to screw-clamps for holdingboiler,sheetn1etal, or other analogous plates while being trimmed, out,or otherwise finished; and it has for its object to so construct one ofthe clamping heads or jaws that both clamping heads or jaws bite orpress evenly throughout their entire clamping surface or area upon theplate placed between them, to more firmly and securely hold the plate inposition while undergoing cutting or finishing, and also to avoid alltorsional strain upon the clam ping jaws or heads and upon theactuating-screw.

My invention accordingly consists of the combination, construction, andarrangement of parts, as hereinafter described and claimed, referencebeing had to the accompanying drawing, which represents a sectionalelevation of ascrew-clamp embodying myimprove ments, the framework ofwhich is partly broken away.

A represents the yoke shaped or other suitably-configured frame orhousing. Upon one limb, a, of said yoke is mounted the fixed clamp jawor head B, which maybe arranged to rotate or not, as desired, and in theother limb, a, is mounted the movable or screwclamp jaw or head 0. Thescrew D and box or bearing E for jaw or head 0 are constructed andarranged for operation in any of the wellknown ways, or as shown.

The jaws or heads B and O are preferably disk-shaped, as indicated,thejaw B being in one piece; but thejaw 0, when large in diameter, ispreferably composed of an outer ring, 0, having central threadedopening, 0, into which screws a plug or center piece, 0 having in itsupper side a semi-spherical socket or chamber, 0 for a ball orsemi-spherical enlargement, d, or the lower end of screw D. The plug orthreaded center piece of disk 0 projects above the top of its ring 0,for engagement with a threaded nut, f, loose on screw D, or on ashoulder, d, at the junction of ball (1 with the screw D. The nut f hasa central socket-opening, f, conforming to the outline of the upper partof the ball or enlargement d, and loosely secures the jaw or head 0 toscrew D, so as to provide a loose ball-and-socket connection for thesame, to admit of turning the screw independently of jaw G, and ofaffording a limited rocking motion for jaw Gin any direction, whereby itmoves or. rocks when brought into impingement with jaw B,

to occupy a plane exactly parallel with that of the jaw B, irrespectiveof whether the jaw B is level or not; and this being the case, itfollows that both jaws or heads will bite each other or a plate, it,placed between them throughout their entire clamping areas or surfaces,and not upon one side or at one portion of their peripheries, as wouldbe the case if the jaw 0 had no rocking motion and the jaw B was more orless out of level.

As the jaws bite throughout their entire clamping-surfaces, they morefirmly and securely clamp the sheet metal placed between them, and alllateral or torsional strain upon the jaws B C and upon screw D isavoided.

What'I claim is- 1. The combination of a yokeframe, A, the fixed jaw B,movable jaw G, screw D, and a ball-and-socket connection between jaw Oand screw D, substantially as set forth.

2. The combination of clampingjaw B, a frame, screw D, having ball end(i, and jaw G, composed of outer ring, 0, threaded center 8 5 piece, 0,and nut f, forming a socket for said ball end, substantially as setforth.

3. In a clamping device, a screw-rod, D, having end d, a head or jaw, G,composed of outer ring, 0, threaded center piece, 0 projecting above thetop of ring 0 and having a socket adapted to screw end 01, and afastening-nut, f, loose on screw D and engaging with said center piece,substantially as set forth.

4. In a screw-clamp for holding sheet-metal 5 plates, a fixed jaw orhead, B, a movable jaw, 0, having a socket, c, exteriorly-threaded nutf, and screw-rod D, having enlarged end d, adapted to socket c and nutf, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

SAMUEL MCCARTER.

Vitnesses:

JOHN J. GORSON, A. O. SHERMAN.

